Chlorhexidine and Mupirocin for Clearance of Methicillin Resistant Staphylococcus aureus Colonization After Hospital Discharge: A Secondary Analysis of the CLEAR Trial

The CLEAR trial demonstrated that a multi-site body decolonization regimen reduced post-discharge infection and hospitalization in methicillin-resistant Staphylococcus aureus (MRSA) carriers. This report describes decolonization efficacy in clearing site-specific MRSA colonization during the trial.We performed a large, multi-center, randomized clinical trial of MRSA decolonization among adult patients after hospital discharge with MRSA infection or colonization. Participants were randomized 1:1 to either MRSA prevention education or education plus decolonization with 4% topical chlorhexidine daily, 0.12% oral chlorhexidine rinse twice daily, and 2% nasal mupirocin twice daily. The intervention was given for five consecutive days twice monthly. Participants were swabbed in the nares, throat, axilla/groin, and wound (if applicable) at baseline, 1, 3, 6, and 9 months after randomization. The primary outcomes of this report are follow-up colonization differences between groups.Among 2,121 participants, 1,058 were randomized to the decolonization group. By one month, MRSA colonization was lower in the decolonization group compared to the education only group (OR = 0.44 [95% Confidence Interval 0.36-0.54, p≤0.001). Similar magnitude of reduction was seen in the nares (OR = 0.34 [0.27-0.42], p 0.001) throat (OR = 0.55 [0.42-0.73], p 0.001), and axilla/groin (OR = 0.57 [0.43-0.75], p 0.001). These differences persisted through month 9 except at the wound site, which had a relatively small sample size. Higher regimen adherence was associated with lower MRSA colonization (p≤0.01).In a randomized clinical trial, a repeated post-discharge decolonization regimen for MRSA carriers reduced MRSA colonization overall and at multiple body sites. Higher treatment adherence was associated with greater reductions in MRSA colonization.